Gas cookers of the above mentioned kind are for example known from DE 601 21 548 T2. The gas cooker described in this document comprises a cooktop with four individual gas burners. Each burner is provided with an individual support element, that can be placed on top of the cooktop for supporting a recipient. A temperature sensor is provided for each burner and extends vertically from the cooktop to be in close contact with the recipient. A gas valve is provided individually for each burner to control the gas flow. The temperature sensor and the gas valve are connected to a control unit, which operates the gas valve on the basis of output values of the temperature sensor. Accordingly, the burner is operated differently throughout different steps of a cooking process without changing the gas flow manually. E.g. the control unit can detect the cooking point of the food inside the recepient by detecting that the sensor output values of the temperature sensor indicate a not rising temperature during operation, so that the gas flow through the burner is reduced and the temperature is maintained to avoid overboiling.
Another embodiment shown in DE 601 21 548 T2 shows a cooktop with four individual burners. Each burner has a support which is formed by four support elements, which are arranged around the burner to receive a cooking recipient located above the respective burner. The support elements are formed integral with the cooktop as cylindrical convexities which are protruding to the upper side of the cooktop. One of the support elements is provided with a temperature sensor for detecting the temperature of the cooking recipient placed thereon. The temperature sensor is located at the upper side of the support element to be in close contact with the recipient. A gas valve is provided individually for each burner to control the gas flow. The temperature sensor and the gas valve are connected to a control unit for operating the gas valve on the basis of output values of the temperature sensor. The general function of the gas cooker according to this embodiment is the same as described above.
Another commonly used gas cooker is described in GB 969 096. It comprises a burner and a support, which is located above the burner for supporting the cooking recipient. The support comprises four legs, which are at their one end side connected to a central ring. On their other end side they are provided with a protruding foot so that an upper supporting surface of the support is provided in an elevated position with respect to the surface of a cooktop. One of the legs is provided with a vertical hole. A temperature sensor extends vertically from the cooktop through the hole to be in contact with a recipient placed on the support. The temperature sensor is connected to a thermostatic control, which operates a gas valve on the basis of sensor output values of the temperature sensor.
During the cooking process the cooktop normally becomes soiled, e.g. by splashes of oil or the like. The major drawback of gas cookers of the above mentioned kind is that their cooktops are difficult to clean. Elements protruding from the cooktop like the temperature sensor represent obstacles which slow down and complicate the cleaning process. At the edges between the cooktop and the protruding temperature sensor, dirt can easily be accumulated and is difficult to remove.
Starting from the above mentioned prior art technology it is an object of the present invention to provide a gas cooker having a cooktop which is easy to clean.